Source Of Suction Research Articles

Experimental investigation of large-scale tornado-like vortices

Tornadoes are one of the most pressing research topics in wind engineering due to the extensive damages they impact on infrastructure and the environment. The proper scaling of experimentally produced tornado-like vortices (TLVs) against actual tornadoes is, therefore, a quintessential part of assessing tornadic damages on the built environment. The Wind Engineering, Energy and Environment (WindEEE) Dome at Western University has already demonstrated its capacity to generate TLVs characterized by length scales in the range between 1:300 and 1:150 by using only a part of the full potential of this simulator. This paper introduces a new experimental mode of the WindEEE Dome operation intending to create larger-scale TLVs in the geometric scaling approximately 1:50. In addition to the six upper fans (source of suction) and the peripheral louvers (source of swirl) that were used in the previous TLV simulations, the new tornado mode of the WindEEE Dome also utilizes the peripheral fans situated along the periphery of the testing chamber as an additional source of angular momentum in the inflow. The simulated TLV is scaled up and compared against published Doppler-radar data of an actual tornado in the United States. Our analyses show that the WindEEE Dome large-scale TLV corresponds to EF0 to EF2-rated twisters in nature. The geometric scale of the produced TLV is ~1:50. This large geometric scale of the TLVs facilitates the experimental investigation of tornadic actions on structures, including aeroelastic testing of wind-structure interactions.

On the magnitude of capillary pressure (suction potential) in tight rocks

In this study, we review the concepts of capillary pressure and total suction. We propose that for shales and siltstones, capillary pressure (matric suction) is not the only dominant source of suction. Therefore, total suction, which is the sum of matric and osmotic pressure (electrostatic forces), provides a better description of the physical process behind water imbibition. We investigate the application of a dew-point psychrometer to measure total suction and compare that to mercury injection capillary pressure (MICP) measurements. The MICP method, traditionally used in energy industry, does not capture the impact of pores smaller than 3 nm. It is also limited to measuring only matric suction, ignoring electrostatic forces. Our results indicate that the suction values typically assumed in the literature from MICP tests significantly underestimate the total suction in shales and siltstones. Total suction for samples from the Montney Formation in Canada can be as high as 250 MPa at water saturations between 1 and 5%. The magnitude of suction measured in this work explains the significant water uptake by this class of reservoirs during hydraulic fracturing. Total suction in the present experiments correlate well to mineralogy and porosity of the samples. The results of this paper suggest that measurements of capillary pressure in unconventional reservoirs are generally inappropriate to describe the behavior of rocks. The order of magnitude of suction reported here has major implications in modelling basin-wide fluid migration, water imbibition into tight rocks, and describing rock's mechanical response after hydraulic fracturing.

Shale Producers Piloting Downhole Compression To Solve Liquid Loading

Almost all gas wells that co-produce liquids share a common and troublesome fate: liquid loading. A new artificial lift technology is being tested across different US shale plays with Equinor to avoid this inevitability. If successful, the system will become a viable alternative to the way in which these wells are produced today. Liquid loading crops up as the natural drive provided via early-stage gas production falls below the point required to move the associated water and/or natural gas liquids to the surface. The problem is progressive, and ultimately leads to a water column in the well. This slows and eventually stops flow until an intervention is executed or if the well is shut in to build up pressure. Though liquid loading occurs in both conventional and unconventional wells, it poses the biggest economic risk to the latter because of the inherently rapid decline rates. After a couple of years, their flow is often only a quarter of what it was during initial production. These are the factors driving Upwing Energy to develop a magnetically driven subsurface compressor system. As explained by Chief Executive Officer Herman Artinian, the company’s technology boils down to this concise concept: “Suck the gas, and the liquids will come with it.” Like all artificial lift systems, the compressor is meant to be used when natural flow has stopped. The Cerritos, California-based Upwing believes that after 2–3 years the bottomhole pressure in most horizontal gas wells is low enough for the compressor to be used as a way to draw down pressure even further, both in the well and the reservoir’s fracture network. “It turns out, the same thing that is happening in the wellbore with the liquid loading is happening inside the reservoir—the little pores are getting liquid loading due to the capillary effect,” explained Artinian. With a constant source of suction, the trapped liquids can be moved from the nanosized pore throats, creating new pathways for free gas flow. Work done so far suggests a pressure-reduction ratio of roughly 3:1 does the job, e.g. a bottomhole pressure of 900 psi would set the compressor’s target at around 300 psi. As the gas and liquids exit the compressor, the increased velocity carries a continuous stream all the way to the wellhead, preventing liquid build up and slugging. Initial field tests of a prototype showed the compressor was able to lift 150 bbl of water per 1•mmscf. “That’s a significant amount of liquids—more than what most unconventional wells are producing today,” said•Artinian. Pilots to Prove Reservoir Response In 2016, shortly after the firm was founded, Upwing tested four prototype compressors in wells in Texas. Production in these wells saw an increase ranging between 30–58%. The aim for the fully developed version is a 75–100% boost in gas output, “which directly translates to a minimum of 10–20% more recoverability of an unconventional well,” said Artinian, adding that the return on investment is expected to be between 6 months and a year.

Main Weaving Nozzles - Ejectors

The paper deals both with numerical flow simulations and experiments in ejectors, used here first of all as main weaving nozzles, further as a source of air suction, etc. The problem of high noise level of expanded air flow is discussed, too.

Macro to nano: a simple method for transporting cultured cells from milliliter scale to nanoliter scale

Microfluidic devices are well-suited for the study of metabolism and paracrine and autocrine signaling because they allow steady or intermittent perfusion of biological cells at cell densities that approach those in living tissue. They also enable the study of small populations of rare cells. However, it can be difficult to introduce the cells into a microfluidic device to achieve and control such densities without damaging or clumping the cells. We describe simple procedures that address the problem of efficient introduction of cells and cell culture media into microfluidic devices using small bore polyetheretherketone (PEEK) tubing and Hamilton gastight syringes. Suspension or adherent cells grown in cell culture flasks are centrifuged and extracted directly from the centrifuge pellet into the end of the PEEK tubing by aspiration. The tube end is then coupled to prepunched channels in the polydimethylsiloxane microfluidic device by friction fitting. Controlled depression of the syringe plunger expels the cells into the microfluidic device only seconds following aspiration. The gastight syringes and PEEK tubing with PEEK fittings provide a non-compliant source of pressure and suction with a rapid response time that is well suited for short-term intramicrofluidic cellular studies. The benefits of this method are its simplicity, modest expense, the short preparation time required for loading appropriate numbers of cells and the applicability of the technique to small quantities of rare or expensive cells. This should in turn lead to new applications of microfluidic devices to biology and medicine.

Dual-Main-Drain Suction-Entrapment Test Report

Life-threatening suction entrapment events have been recorded in swimming pools and spas since before World War II, although formal documentation and investigation did not occur until the Consumer Product Safety Commission began maintaining National Electronic Incident Surveillance System data. Of 147 incidents documented between 1985 and 2002, 36 incidents, 1 in 4, were fatal. Suction entrapment occurs in wading pools, spas, or swimming pools when a person’s body blocks the flow of water from a pool or spa to the circulation pump. When the source of suction to the pump is blocked, the pump continues to operate creating a strong suction on whatever is blocking the water flow. The dual-main-drain-suction-entrapment tests were developed to determine the effectiveness of dual main drains as a means of avoiding suction-entrapment accidents.

An alternative approach for chest drainage after cardiac surgery: Redon drains

At the end of every cardiac procedure, two or three chest tubes (28F–32F) are typically placed in the mediastinum to continuously monitor postoperative blood loss and to prevent undesirable blood collection, especially in the pericardial space, which could potentially lead to cardiac tamponade. The chest tubes are connected to various drainage systems that use the underwater valve seal principle. Suction of about −20 cm H2O is usually applied. Here we present an alternative drainage system that provides distinct advantages over the commonly used systems. The drainage system consists of four or five Redon (B. Braun Melsungen AG, Melsungen, Germany) drains (2-mm inner diameter). Each drain is connected to a 600-mL reservoir with an applied suction of −800 mbar (816 cm H2O) (Figure 1). They are placed into the pericardial space (and pleural cavity, if needed) in the following sequence (Figure 2):1Drain 1 is positioned along the right heart border (right atrium), ending under the ascending aorta.2Drain 2 is positioned in front of the heart directly beneath the sternum.3Drain 3 is positioned along the diaphragmatic surface of the heart, ending over the lateral wall of the left ventricle.4Drain 4 is positioned in front of the heart (right ventricle), curving behind the pulmonary artery and ending in the sinus transversus.5Drain 5 (pleural, only if needed) is placed into the desired pleural space through a cauterized hole in the back wall of the pericardial sac, ending over the diaphragm.Figure 2Arrangement of the drains in the mediastinum.View Large Image Figure ViewerDownload Hi-res image Download (PPT) All drains exit the mediastinum through the abdominal fascia in the epigastric area. Drains are removed on the second postoperative day, being first disconnected from the reservoir to ensure that no continuous suction is applied during their removal. A total of 4297 cardiac procedures were performed between February 2002 and January 2007 at our institution. Redon drains were used for postoperative blood drainage in all cases (99.8%), regardless of the type of operation, with the only exceptions being 9 patients in whom it was not possible to control the coagulation disorder after weaning from cardiopulmonary bypass and who therefore required the use of a cell salvage device immediately after the procedure in the operating room and subsequently in the intensive care unit. Chest tubes (32F) were used in these 9 patients. The postoperative total blood losses at the time of Redon drain removal (usually on postoperative day 2) are summarized in Table 1. Postoperative bleeding complications for the cohort of 4297 patients in whom a Redon drainage system was used are listed in Table 2.TABLE 1The mean postoperative blood loss at the time of Redon drain removal (National Cardiac Surgery Registry 2002–2006)Type of procedureBlood loss (mL)CABG971.3Valves1057.6Thoracic aorta1153.9Redo procedures1497.6CABG, Coronary artery bypass grafting. Open table in a new tab TABLE 2Postoperative bleeding complications in patients in whom a Redon drainage system was used (n = 4297) (National Cardiac Surgery Registry 2002–2006)No. (%) of patientsReopening for bleeding119 (2.8%)Reopening for tamponade29 (0.7%) Open table in a new tab CABG, Coronary artery bypass grafting. Below, we summarize our experiences with the advantages and disadvantages of Redon drains relative to standard drainage approaches (using an underwater valve seal). 1The handling is more convenient. Once the drains are connected and checked for tightness (absence of air leaks), there is no need for further monitoring such as checking the water levels or the functioning of the water valve seal.2The Redon drainage system allows regions of bleeding to be detected. Each drain covers a specific area around the heart, facilitating the localization of any bleeding sources (eg, coronary suture line or left atrium suture line).3It decreases the risk of local tamponade. Positioning the drains over all the heart chambers, especially the right and left atria, decreases the risk of local tamponade.4It decreases the risk of coronary graft compression. The drains are thinner and more flexible, decreasing the risk of graft compression.5It maintains suction during patient transportation. There is no need for an external source of suction, which enables the suction to be maintained when transporting the patient from the operating room to the intensive care unit.6It is noiseless. It produces no bubbling sounds that are disturbing for both medical personnel and the patient.7It is cost-effective. The Redon drain system is five times cheaper than drainage using chest tubes. 1The Redon drain system is sensitive to air leaks. The presence of an air leak from the lung tissue will result in inadequate suction, requiring the system to be converted to the underwater drainage principle (external suction).2It cannot be used with a cell salvage system. In cases of profound bleeding resulting from coagulation disorder, the system cannot be used with a cell salvage device. Because of the distinct predominance of the advantages of the described system over its disadvantages, we highly recommend its broader use. Dr Gwozdziewicz

Escape strategies in co‐occurring calanoid copepods

We show how four co‐occurring calanoid copepod species modulate their responses to two contrasting hydrodynamic stimuli. Species‐specific patterns in escape behavior included quantitative differences in performance to each stimulus type. Using high‐speed video, we compared escape reactions in Acartia hudsonica, Centropages hamatus, Tortanus discaudatus, and Temora longicornis. Responses to a flow field created by a suction tube involved reorientation away from the source of suction followed by a series of vigorous power strokes. Responses to brief computer‐controlled hydrodynamic stimuli had short latencies (a few milliseconds) and consisted of a reorientation followed by a few pereiopod power strokes. Two species responded to this stimulus with higher escape speeds. The other two species gave a larger response to the suction stimulus by producing long escape trajectories. Each species perceived the magnitude of the threat in a different way and employed a different strategy in the escape response.

Noise reducing aspirator

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The "Advertised" Self: Wyndham Lewis' Satire

When Wyndham Lewis, the British painter, novelist, popular philosopher, and polemicist, wrote on satire in 1934, he seized upon a critic's designation of him as a personal-appearance satirist. That is not an insult, Lewis said: it is a compliment. Call him a 'personal-appearance writer' and he is far from being displeased. 1 Apparently Lewis' fellow satirists were no less displeased, for characterization by outward appearance, by type, was common to the major satirical novelists of the early twentieth century: to Evelyn Waugh, Ronald Firbank, Aldous Huxley. Indeed, it has been one of the chief characteristics of all satiric writing-and it has sometimes been called satire's chief disability. Lewis' complex motives for exterior portrayal can be discovered more readily than those of many other writers, and they provide a pattern of the cultural and psychological sources of modern satire. The first crucial biographical fact about Wyndham Lewis is that he was a Vorticist painter. was one of many avant garde movements that occurred in England during a remarkable period of artistic innovation and activity which began, essentially, with the first Post-Impressionist exhibition organized by the Bloomsburian Roger Fry in 1910, and ended with the beginning of World War I in 1914. Vorticist paintings are compositions of hard, angular, geometric designs-planes, triangles, and concave figures superimposed upon one another, and all of them bending, collapsing, spinning down and back into a vortex, a source of suction and energy. Often the paintings appear to represent building facades and structural girders, some of them crumbling, as in Lewis' painting Revolution (The Crowd). At other times we look into spiraling or descending staircases. The human figures possess no soft or rounded surfaces; they are caught in angular poses, often of tension, always faceless and cubistically disjointed. Vorticism accepted the machine world, Lewis observed. It sought out machine forms.

The nurse's role in immediate postoperative care.

From the time that a patient leaves the care of the anaesthetist after an operation until he wakes in the ward his physiological state should be continuously and expertly supervised. Postoperative nurses are provided only when the operating theatre has a recovery room. A survey among consultants and nurses in one region showed that many surgical units did not have recovery rooms and that inexperienced ward nurses were often sent to collect patients. The survey showed that most nurses were competent to care for unconscious patients so long as an emergency did not arise. In many hospitals the facilities for the safe nursing of postoperative patients were totally inadequate. The very least that is needed is good communications with the anaesthetist, adequate lighting, and a source of oxygen and suction. Because of the shortage of nurses likely to have to care for postanaesthetic patients early on and to train them accordingly. Nevertheless, recovery nurses, whose sole responsibility is to care for a patient until be has recovered from anaesthesia, should be appointed for all busy surgical units.

Nasal, nasopharyngeal and throat suction apparatus for the newborn and small infant.

REMOVAL of excessive quantities of foreign material, such as mucus, blood, or regurgitated formula, from the upper respiratory passages of infants is not a new problem. In the hospital suitable suction apparatus for this purpose is usually available, but in the home or the office, when faced with emergencies, the pediatrician often has no quick, safe, and adequate source of suction. Because it was recognized that in such difficult circumstances a conveniently portable and inexpensive suction apparatus might well be lifesaving, the bulb suction apparatus was developed. It is neither too bulky nor too expensive for ownership by the practitioner. APPARATUS The apparatus (Fig.)1has been designed as simply as possible in order to aid the physician working alone and to facilitate cleaning and care of the equipment. It is composed of a round-tipped, multiple-opening catheter which is attached to the suction bulb by a glass adapter. The catheter

QUANTITATIVE EFFECTS OF PHYSICAL AND CHEMICAL AGENTS ON THE ERECTILE TISSUE RESPONSE IN THE NOSE

In previous communications¹a new and simple manometric method was described for the accurate measurement of nasal aerodynamics. It was shown that by this method one could determine the comparative shrinkage efficiency of vasoconstrictor drugs commonly used in the treatment of nasal obstruction.²Before investigating the specific action of these drugs as administered by means of nasal sprays, it appeared essential to evaluate the physiologic effects of certain factors, such as (<i>a</i>) air pressure and (<i>b</i>) the tonicity of a solution, on the erectile tissue response of the inferior turbinate. The present study deals with an investigation of these factors. <h3>METHOD OF STUDY</h3> The apparatus (fig. 1) used was made up of a nasal catheter (<i>F</i>) with glass olive tips of suitable size; a standard flowmeter, to measure the volume of air flow (liters per minute); a convenient source of suction (<i>V</i>) and a series of two manometers, inclined {E)

Month in the Patent Office

In an airscrew wherein the pitch angle varies from root to tip of the blade, openings are provided on the upper surface of each blade and near the trailing edge, and extend from the root for a part of the length of the blade and communicate with an inwardly extending duct to a source of suction or depression. The blade a is provided with a series of openings a1 on its upper surface near the trailing edge, such openings communicating by a central duct a11 with a hollow boss and thence by openings a12 with a carrier box b fixed to the engine. The box b has a passage b1 connected by pipe c with the induction pipe of the driving engine. It may, however, be connected with a suction pump or other means of reducing the pressure. The area of the openings a1 may be varied by means of shutter e, slidable in a slot e3 to control the opening. This shutter e is guided by pin‐and‐slot mechanism e1, e2 and is actuated by rod e4 coupled to a screw e5 movable in a nut member e6 having an external toothed centre e9 engaging a control rack e8. This arrangement may be used with a fixed or with a variable‐pitch propeller.

A Receiver Unit for the Determination of Lactic Acid.

The analytical methods for determination of lactic acid have been greatly improved in the last few years, notably by Clausen; Friedemann, Cotonio and Shaffer; Davenport and Davenport; and Friedemann and Kendall. The receiver unit here described was designed for use with the Friedemann, Cotonio and Shaffer apparatus and procedure. When small amounts of lactic acid are to be determined, better checks have been obtained by this method than by the use of other types of receivers. A marked advantage lies in the fact that its use involves a minimum of dilution of the receiver contents, through simplification of washing. This is important, because the end point of the iodine titration is sharper the lower the volume of liquid titrated. The receiver consists essentially of a 5/16” × 6” test tube, carrying a 2-hole rubber stopper. Through one of these holes there runs a glass tube, drawn into a capillary as soon as it passes the stopper, and extending to the bottom of the tube. The other hole carries a trap, which leads to the source of suction. In an analysis each such receiver contains 10 ml. of 1.0% sodium bisulphite. Accordingly the incoming gases are drawn through a column of bisulphite at least 10 cm. high, in the form of a stream of small bubbles. The fineness of these bubbles insures a large ratio of surface area to volume, which favors absorption. If the suction be properly regulated, no liquid will be drawn up into the trap, yet a steady stream of bubbles can be maintained. At the end of a run the tubes are emptied into 125 ml. pyrex Erlenmeyer flasks, the receiver is washed out twice with 2 ml. of wash water, and the titration is carried out in the usual way.